Blueberries have an antiestrogenic effect

[JWSimpkins]

The phenols in blueberries make cells less sensitive to the detrimental effects of estradiol, but leave the desirable effects of the hormone intact. It's possible to draw this conclusion from an animal study done by oncologists at the University of Louisville in the US, which will soon be published in the Journal of Agricultural and Food Chemistry.

http://www.ergo-log.com/blueberries-have-an-antioestrogenic-effect.html